public class SelectionSort {

    private SelectionSort() {
    }

    public static <E extends Comparable<E>> void sort(E[] arr) {

        // arr[0...i) 是有序的；arr[i...n) 是无序的
        for (int i = 0; i < arr.length; i++) {

            // 选择 arr[i...n) 中的最小值
            int minIndex = i;
            for (int j = i; j < arr.length; j++) {
                if (arr[j].compareTo(arr[minIndex]) < 0)
                    minIndex = j;
            }

            swap(arr, i, minIndex);
        }
    }

    private static <E> void swap(E[] arr, int i, int j) {

        E t = arr[i];
        arr[i] = arr[j];
        arr[j] = t;
    }

    public static void main(String[] args) {

        Integer[] arr = {1, 4, 2, 3, 6, 5};
        SelectionSort.sort(arr);
        for (int e : arr)
            System.out.print(e + " ");
        System.out.println();

        Student[] students = {new Student("Alice", 98),
                new Student("Bobo", 100),
                new Student("Charles", 66)};
        SelectionSort.sort(students);
        for (Student student : students)
            System.out.print(student + " ");
        System.out.println();
    }
}
